1. Field
The present general inventive concept generally relates to a lens barrel and an optical appliance.
2. Description of the Background
An inner focus zoom lens among a plurality of lenses arranged in a lens barrel performs zooming and focusing by moving a zoom lens (variator) and a focus lens in an optical axis direction.
Such an inner focus zoom lens is widely being used in an optical appliance, such as a photographing apparatus including a digital video camera and a digital still camera, or an image projecting apparatus including a projector, since the entire length of the inner focus zoom lens is not subject to change by focusing, and the inner focus zoom lens can contribute to miniaturization and lightness of the lens barrel and the optical appliance.
Also, the zoom lens has a hand shaking compensating (image shaking compensating) operation to compensate for image shaking caused by hand shaking by moving some lenses in a perpendicular direction with respect to an optical axis.
However, the lens barrel, which has the zoom operation or the hand shaking compensating operation as described above, includes a lens retaining member, which retains a lens, a fixing cylinder, which receives the lens retaining member therein and has a guide slit engaged with a guide pin protruding from an outer circumference of the lens retaining member, and a cam cylinder, which is rotatable around an outer circumference of the fixing cylinder in a circumferential direction while receiving the fixing cylinder therein, and which has a cam slit engaged with the guide pin protruding from the guide slit. In the lens barrel, the guide pin is relatively moved in the guide slit and the cam slit by rotating the cam cylinder so that the lens retaining member is moved in the fixing cylinder in the optical axis direction.
The lens barrel mounts thereon a driving unit, such as a focus actuator unit to displace the lens in an optical axis direction while performing focusing or an anti-vibration actuator unit to displace the lens in a perpendicular direction to the optical axis while compensating for hand shaking.
As such, it is important to compactly arrange the parts, such as the lens retaining member, to retain the lenses or the driving unit to drive the lenses and arrange the parts in the fixing cylinder to make the lens barrel smaller and lighter.
In the case that the parts are integrated into a single unit, the lens barrel can achieve miniaturization or lightness due to the simplified structure and the reduced number of parts. However, in the case that the driving units, such as the focus actuator unit and the anti-vibration actuator unit are arranged adjacent to each other in the fixing cylinder, there is a problem that the driving units harmfully affect each other due to their respective vibrations while detecting each other's locations.